1. Field of the Invention
The invention relates to downhole oil field tools. More particularly, the invention relates to performance enhancing devices for inflatable elements.
2. Prior Art
Inflatable elements such as packers have been known and used in the hydrocarbon production industry for a substantial period of time. During this time they have been reliable and favored by oil well operators in many sealing operations. Prior art inflatable elements have however had difficulty with setting in noncylindrical boreholes. Noncylindrical boreholes include oval boreholes, unconsolidated boreholes, windows, etc. The problems of the prior art inflatable elements in noncylindrical boreholes has been that the rubber of the inflatable boot is extruded through the ribs of the element. This can cause severe damage to the rubber of the boot and to the ribs of the element and may result in failure of the device. Thus, the art is in need of a means to avoid extrusion of the rubber boot of the inflatable element through the rib portion of the inflatable element during inflation of a tool in a noncylindrical environment.
The above-identified drawbacks of the prior art are overcome or alleviated by the extrusion resistant inflatable tool of the invention.
In the invention, a biaxially woven sleeve is interposed between the boot/inner-tube and the ribs of a tool having otherwise conventional components. The sleeve is preferably constructed of carbon fiber, aramid fiber, fiber glass or suitable alternative fiber which provides a bridge between the ribs of the inflatable tool as the element expands into the noncylindrical environment. The existence of the biaxially woven sleeve in an annular area outside the boot and inside the ribs of the element prevents the boot from being extruded through the ribs when they open excessively during expansion into a noncylindrical borehole environment. The sleeve further prevents excessive bending of the ribs which would otherwise create difficulties in removing the tool from the downhole environment.